Elastic polymer materials are useful in absorbent articles. Elastic polymer strands or films can be used, for instance, in waist and leg regions of a wearable absorbent article such as a diaper. The resulting elastic waist and leg regions provide a secure fit to the user. This helps stop leaking as well as makes the diaper more comfortable.
Absorbent articles contain many materials and the manufacturing process can be complex and expensive. Manufacturing methods that simplify production and reduce cost are desired. One method of making elastic laminates involves stretching an elastic material, such as a strand or film, and bonding the stretched material to a fabric sheet to create an elastic laminate. Some elastic polymers, when stretched, will maintain the stretched, or latent, state until heat is added to restore the elasticity. Heating latent polymers to restore elasticity is useful in producing absorbent articles but this process can also require numerous production steps and can become expensive.
Microwave energy has primarily been used for food processing. Microwave sensitive materials have been used to increase microwave heating rate and uniformity. Most microwave sensitive materials are inorganic chemicals and are typically coated onto a substrate to form a microwave interactive layer. Often times there is little control over the amount of heat produced by these materials, which can result in inadequate heating or overheating and burning.
There is a need in the absorbent article industry for new ways to heat latent polymer materials quickly and efficiently.